Feeds

Oceans gaining ACID faster than last 300 MILLION YEARS

Atmospheric CO2 cast as the culprit (again)

High performance access to file storage

The world's oceans may be experiencing a rate of acidification unparalleled in the past 300 million years, according to a paper published on Thursday in the journal Science.

"The geological record suggests that the current acidification is potentially unparalleled in at least the last 300 million years of Earth history," co-author Andy Ridgwell of Bristol University told AFP, "and raises the possibility that we are entering an unknown territory of marine ecosystem change."

The paper's lead author, Bärbel Hönisch of Columbia University's Lamont-Doherty Earth Observatory, noted in a university release that during the past century, ocean pH has fallen by a tenth of a unit to 8.1 – and as all science-minded Reg readers are aware, pH is measured on a logarithmic scale, so a drop of 0.1 units is significant, indeed.

The acidification change-rate noted in the study is at least 10 times faster than that which occurred during the Paleocene-Eocene Thermal Maximum (PETM), which the globe experienced around 56 million years ago, Hönisch said.

During the PETM, mass extinctions occurred on both land and sea. The causes for that acidification surge are not well understood, but one prime suspect is a series of massive methane bursts from ocean sediment, which were triggered by volcanic activity.

The cause of the current acidification is more clear, the study maintains. As Hönisch points out, atmospheric CO2 has risen about 30 percent in the past century to 393 parts per million. The ocean soaks up massive amounts of that gas, which reacts with seawater to form carbonic acid.

That acid will eventually be neutralized, but if the balance of the rates of neutralization and CO2 absorption leans more towards the latter, the report says, the levels of the carbonate ions that various sea creatures require for growing their shells and building coral reefs can be thrown out of whack.

"If industrial carbon emissions continue at the current pace," Hönisch says, "we may lose organisms we care about – coral reefs, oysters, salmon."

Although CO2 increase is cast as the trigger for runaway ocean acidification, it's a pheomenon that's separate from that of the radiative forcing caused by CO2, methane, nitrous oxide, and other factors cited by the Intergovernmental Panel on Climate Change (IPCC) 2007 report and other studies, and blamed for widely accepted increases in global temperatures.

It's estimated that the oceans' acidity rose by a massive 0.45 units during the PETM. The IPCC has estimated that pH may – may – drop another 0.3 units by the end of this century, should atmospheric CO2 concentrations continue to increase.

Since it's impossible to fully understand what caused the PETM and its mass extinctions, this paper's conclusion may be dismissed by some as an example of "confirmation bias", as it's called in scientific circles, by oceanic scientists concerned about rising ocean acidification as it relates to increases in atmospheric CO2.

That said, a 2011 study of reefs in Papua New Guinea showed that when the pH around reefs there dropped to 7.8 due to shallow volcanic CO2 seeps – an acidification level that, the study says, would require atmospheric CO2 to soar to around 750ppm – biodiversity dropped by as much as 40 per cent.

Not that ocean life as we know it is doomed to a watery grave. Some organisms, in fact, can benefit from a more-acidic environment. "We know that life during past ocean acidification events was not wiped out – new species evolved to replace those that died off," Hönisch said.

While that may be encouraging to those worried about a CO2-induced Armageddon, it's cold comfort to those species that may face a PETM II extinction. ®

High performance access to file storage

More from The Register

next story
Elon Musk's LEAKY THRUSTER gas stalls Space Station supply run
Helium seeps from Falcon 9 first stage, delays new legs for NASA robonaut
Solar-powered aircraft unveiled for round-the-world flight
It's going to be a slow and sleepy flight for the pilots
Russian deputy PM: 'We are coming to the Moon FOREVER'
Plans to annex Earth's satellite with permanent base by 2030
LOHAN's Punch and Judy show relaunches Thursday
Weather looking good for second pop at test flights
Saturn spotted spawning new FEMTO-MOON
Icy 'Peggy' looks to be leaving the outer rings
Discovery time for 200m WONDER MATERIALS shaved from 4 MILLENNIA... to 4 years
Alloy, Alloy: Boffins in speed-classification breakthrough
India's GPS alternative launches second satellite
Closed satnav system due to have all seven birds aloft by 2016
Curiosity finds not-very-Australian-shaped rock on Mars
File under 'messianic pastries' and move on, people
Top Secret US payload launched into space successfully
Clandestine NRO spacecraft sets off on its unknown mission
prev story

Whitepapers

Securing web applications made simple and scalable
In this whitepaper learn how automated security testing can provide a simple and scalable way to protect your web applications.
Five 3D headsets to be won!
We were so impressed by the Durovis Dive headset we’ve asked the company to give some away to Reg readers.
HP ArcSight ESM solution helps Finansbank
Based on their experience using HP ArcSight Enterprise Security Manager for IT security operations, Finansbank moved to HP ArcSight ESM for fraud management.
The benefits of software based PBX
Why you should break free from your proprietary PBX and how to leverage your existing server hardware.
Mobile application security study
Download this report to see the alarming realities regarding the sheer number of applications vulnerable to attack, as well as the most common and easily addressable vulnerability errors.